A connecting rod, or lost motion cylinder, is a hydraulic cylinder used in a mechanical drive system. It replaces a cam and a cam follower. The cylinder has no hydraulic pressure applied to it, but uses return hydraulic oil as lubrication, and is mechanically operated. The greatest problem with such a cylinder moving back and forth and not being under pressure but being driven mechanically is that it will destroy itself quickly by banging hard each time the cylinder advances or retracts.
Some efforts have been made to "cushion" the cylinder by trapping oil inside and by having the end of the stroke trap oil in the cylinder and then bleed it out through a needle valve. This system is very expensive to fabricate.
It is therefore a principal object of this invention to provide for the cushioning of a lost motion cylinder which is relatively inexpensive to install, fabricate, and to replace if necessary.
A further object of this invention is to provide a flow control element to restrict the amount of oil flowing in the hydraulic return line to provide the cushioning effect for the lost motion cylinder.
These and other objects will be apparent to those skilled in the art.